CHIA MUCILAGE (Salvia hispanica L.) AS A WALL MATERIAL FOR THE MICROENCAPSULATION OF α-TOCOPHEROL VIA FREEZE-DRYING

The food industry's interest in bioactives, such as α-tocopherol, has increased in recent years due to their ability to mitigate risks associated with chronic diseases, such as cardiovascular diseases and cancer. Water insolubility and instability in the presence of oxygen, moisture, temperature, and light make it challenging to incorporate these compounds into foods, and encapsulation is a viable alternative to protect bioactives and disperse them in water-rich foods. Chia mucilage (Salvia hispanica L.) (MC) is rich in polysaccharides and proteins and has potential as a natural product for encapsulation. In this context, the objective of this work was to evaluate the capacity of MC associated with whey protein concentrate (CPS) as wall material for the encapsulation of α-tocopherol. To this end, emulsions with 12% solids (MC and CPS) and 8% oil phase were lyophilized. The concentration of MC was 0.5, 1.0, and 1.5% (m/m) and that of CPS was 10.5, 11.0, and 11.5% (m/m), and the oil phase was composed of corn oil or soybean oil enriched with α-tocopherol (10% m/m of the lipid fraction). The emulsions were characterized in terms of viscosity, turbidity, oil droplet size, and stability. For the microparticles, analyses of drying yield, water activity, moisture, hygroscopicity, encapsulation efficiency, color, apparent density, Fourier transform infrared spectroscopy, and scanning electron microscopy were performed. The results showed that increases in the concentration of MC contributed to the increase in viscosity and turbidity of the emulsions, as well as the reduction in the size of oil droplets and stability of the treatments, indicating greater stability of these emulsions. There was no significant difference (p > 0.05) between the treatments for drying yield, apparent density, and hygroscopicity. The water activity of all samples was equal to or less than 0.25 and is within the safe range for lipid protection (0.35). Higher moisture contents (2.11% and 1.87%) were found for treatments with 1.5% MC and 10.5% CPS. The microparticles exhibited reddish and yellowish tones, spherical shape with irregular size. FTIR analysis confirmed the encapsulation of α-tocopherol with efficiency ranging from 57.47% to 71.53%, with the highest value found for treatments with 1.0% MC and 11.0% CPS. The results confirmed the feasibility of applying the freeze-drying method for the encapsulation of α-tocopherol using MC as the wall material.